My 80 has filter ring damage, Hasselblad filters will go on, but they bind and are a bear to take off. Aftermarket filters go on and off with no problem. The fit on Hasselblad filters is pretty precise, so if 7 different filters won't mount correctly, it's most likely the lens, as has been surmised.
One solution I have considered is getting an ugly condition filter from KEH, removing the glass and semi-permanently putting it on the lens. For my 80 the thing that holds me back is concern for vignetting, but that wouldn't be as much problem on a 150.